This invention relates to an article storage and dispensing device for refrigerated articles from a vending machine, and more particularly, to a primary device for detecting a sold out situation of the stored articles which is suitable for use in a helix-type storage and dispensing device.
Helix-type article storage and dispensing devices are well known in the prior art. For example, U.S. Pat. No. 3,335,907 issued to Holstein et al. discloses a transversely disposed helix-type dispensing device. In this dispensing device, an article storage cabinet has a discharge opening in one side plate and helical element transversely extending within the cabinet. One end of the helical element is connected to a driving device to cause rotating motion of the element. During rotating motion of the helical element, the articles stored in the gaps between the spirals of the helical element are moved toward the discharge opening and the most outwardly positioned article is discharged through the discharge opening. In this construction of an article dispensing device, means for detecting an empty situation of the stored articles is normally provided on the device to stop the vending mechanism and indicate the empty situation to customers. One basic construction of a detecting device is disclosed in U.S. Pat. No. 2,564,552 issued to H. Verdery.
Referring to FIG. 1, the basic construction of a prior art detecting device is disclosed. The storage space S formed in cabinet 1 extends vertically and a helical element 2 is disposed within cabinet 1 to extend vertically. Cabinet 1 has an article loading opening 3 in the front plate 1a which is normally closed by a door 4, and a discharge opening at its lower end to discharge the articles. The upper end of helical element 2 is connected to the driving means (not shown) disposed on the upper plate of cabinet 1 through a coupling device 5 connected to the driving means by pin 6. A detecting plate 7 is pivotally supported in cabinet 1 extending within the storage area S of cabinet 1. Generally, detecting plate 7 is pushed toward the rear plate 1b of cabinet 1 by the stored articles A but if all of the stored articles have been dispensed and the cabinet is empty, detecting plate 7 swings in close to helical element 2, this position being indicated by number 7' in FIG. 1.
Therefore, if a microswitch or other switch element is mounted on the rear plate 1b of cabinet 1 in contact with detecting plate 7, the empty situation of stored articles is easily detected by the movement of detecting plate 7. The general construction and operation of an empty switch is disclosed in U.S. Pat. No. 2,564,552.
If the above mentioned article storage and dispensing device is used in a refrigerated article vending machine, the drops of water caused by condensation while door 4 is opened to load the articles adhere to or condense on the inner surface of rear plate 1b. As the refrigerating operation continues to maintain the predetermined temperature in storage space S, the water of condensation fills the gap between rear plate 1b and detecting plate 7, cools down and finally freezes. As a result of the buildup of the frozen water droplets, detecting plate 7 becomes rigidly affixed on the rear plate 1b due to the frozen drops of water. Thus, even if the stored articles are all dispensed and the dispensing device has no articles left therein, the vending machine is still held in the operating condition. Thus, the customers cannot recognize the empty situation.
A prior detecting device construction has been explained with reference to one type of helix-type dispensing device. However, as shown in FIG. 2, this detecting device can be used not only with a single stored row dispensing device but also with a plural stored row dispensing device. Also, if the dispensing device has plural stored rows, plural detecting devices may be disposed in the cabinet facing each of the rows, respectively.